Toby Spribille of the University of Graz in Austria and his colleagues were trying to understand why two species of lichen that were made up of the same species of mycobiont and photobiont were differently coloured and contained varying levels of a toxin known as vulpinic acid.
Using an approach that examined the messenger RNAs produced by the organism, they tried to find the genes that produced the toxin, but neither the mycobiont or the photobiont had genes that matched the transcript.
By broadening their search to include other types of fungi, they found genes belonging to a rare fungus called a Cystobasidiomycete. Unable to see the cells responsible for this unusual finding, they used fluorescent in situ hybridisation FISH to light up cells containing genes for the algae, the ascomycete and the cystobasidiomycete. By linking different colours to each organism, they produced videos showing the distribution of each cell type.
The new fungus existed as single cells inside the cortex, where it may play a structural role as well as providing chemical defence. It is hard to overstate the importance of this discovery. Spribille was quoted in the New York Times as saying that lichens are as diverse as vertebrates. And yet we did not know until now that the symbiosis that allows lichens to exist has more than two partners. The authors have described a new order of fungi called the Cyphobasidiales.
It is not everyday that scientists are able to add new taxa at such a high level. It is like discovering the Primates. Lichens have a body called a thallus, an outer, tightly packed fungal layer called a cortex , and an inner, loosely packed fungal layer called a medulla Figure 1. Lichens use hyphal bundles called rhizines to attach to the substrate.
Lichens are classified as fungi and the fungal partners belong to the Ascomycota and Basidiomycota. Lichens can also be grouped into types based on their morphology. There are three major types of lichens, although other types exist as well. Lichens that are tightly attached to the substrate, giving them a crusty appearance, are called crustose lichens. Those that have leaf-like lobes are foliose lichens ; they may only be attached at one point in the growth form, and they also have a second cortex below the medulla.
Finally, fruticose lichens have rounded structures and an overall branched appearance. Figure 2 shows an example of each of the forms of lichens. Figure 2. Examples of the three types of lichens are shown here.
The doctor explains that ringworm is a general term for a condition caused by multiple species. The first step is to take a scraping for examination under the microscope, which the doctor has already done. He explains that he has identified the infection as a fungus, and that the antifungal cream works against the most common fungi associated with ringworm. However, the cream may not work against some species of fungus. If the cream is not working after a couple of weeks, Anthony should come in for another visit, at which time the doctor will take steps to identify the species of the fungus.
Positive identification of dermatophytes requires culturing. These features suggest that the fungus is Trichophyton rubrum , a common cause of ringworm. Skip to main content. Photo by Chris Wagner, U. Forest Service. Algae are in another kingdom Protista separate from plants and fungi.
There are several types of algae: green, brown, red, gold. They can survive in salt water and in freshwater on their own, and in any environment when part of a lichen relationship. Although cyanobacteria are called blue-green algae, they are actually bacteria, and are part of the bacteria kingdom, Monera.
The "blue" in the common name refers to the fact that they need to live in water, and "green algae" refers to their photosynthetic abilities, like green algae. Peltigera britannica , dog-pelt lichen. Notice the bright green surface that is green algae showing through.
Look closely and you will see dark spots. Those spots are pockets of cyanobacteria. Photo by Karen Dillman, U. Isn't lichen that mossy stuff on rocks and trees? When people think of lichens, many of them think of them as a kind of moss.
That could not be further from the truth. Although moss and lichens are both called non-vascular plants, only mosses are plants. Mosses are included in a group of non-vascular plants called bryophytes. Mosses are believed to be the ancestors of the plants we see today, like trees, flowers, and ferns.
Lichens, on the other hand, are not similar in any way to mosses or other members of the plant kingdom. Cladina arbuscula , a lichen, is also known as reindeer moss. In this picture, it is surrounded by real moss. This species is rare in Colorado. Photo by Gay Austin, U. Look closely at this moss.
Notice how leaf-like it is. The structures on top produce spores. They are the main mode of moss reproduction. Photo by Charles Peirce, Michigan Wildflowers.
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